1. Field
Example embodiments relate to methods and apparatuses for manufacturing a light emitting device having improved light emission efficiency.
2. Description of the Related Art
A semiconductor light emitting device generates minority carriers that are injected by using a p-n junction structure of a semiconductor, and emits light by recombination of the minority carriers. The semiconductor light emitting device may be largely divided into a light emitting diode and a laser diode, and the light emitting diode is used as a highly efficient and environmentally-friendly light source in various fields including displays, optical communications, automobiles, and illumination, because the light emitting diode consumes a relatively low amount of power but has relatively high luminosity.
A light emitting device has to have improved light emission performance, and light emission efficiency may be one standard used to determine the light emission performance of the light emitting device. The light emission efficiency is mainly determined by three factors of internal quantum efficiency, extraction efficiency, and an operation voltage. The internal quantum efficiency indicates a characteristic value regarding how many photons are generated with respect to electrons that pass through the light emitting device, and may be determined by a quality of a semiconductor material, and a design of an active region. The extraction efficiency indicates a rate of the amount of photons that partly flow out of a semiconductor chip. The photons that are generated due to a relatively high refractive index difference between the semiconductor and a peripheral material may be absorbed into the semiconductor chip while being internally reflected several times. Thus, the extraction efficiency may be limited by the photons that are lost during the multi-reflection process in the semiconductor chip or during the absorption process. The operation voltage may be determined by an energy band gap of the active region, and electric resistance of the light emitting device.